|SUN Xinmin / Director of Henan Provincial Institute of Cultural Relics and Archeology
|The Ru kiln was foremost among the five great kiln centers of the Song dynasty, and the fame of its wares spread through the world together with Guan, Ge, Ding, and Jun wares. During the Tang and Song Dynasties, it became popular to refer to porcelain wares by the name of the Region or Zhou where their respective kilns were located. Thus we speak of “Ru ware” because during the Northern Song the kiln was located in Ruzhou, i.e., Ru Region. The Ru kiln site, which was discovered in 1950 by Chen Wanli, is located in Qingliangsi Village, Daying Township, 25 km west of the county seat of Baofeng County, Henan. Confirmation that this was indeed the remains of the Ru kiln came in 1987, during the first excavation of the site. In 2000, during the sixth excavation, the central porcelain-firing area was found. Ru porcelain is famed for the thinness and purity of its clay bodies, the fine workmanship in shaping, and the pure sky-blue color of its glaze. The latter was praised in the classic phrase, “like the blue of the sky in a clearing amongst the clouds after rain.” The glaze surface always featured very fine, complex crackelure that suggested fish scales or the fine cracks in ice. Moreover, an exquisite level of workmanship went into the vessels’ making. The glaze covered the whole surface, including the feet, and the support pins on which they were fired were as fine as sesame grains. Thus, from Song times to the present, they were widely praised and admired. During the Qing dynasty, the Qianlong emperor once had 183 of his poems inscribed on 16 of his most prized porcelains, and of these, 15 were Ru ware. This is a reflection of the esteem that Ru ware enjoyed among emperors and scholar-officials during the Ming and Qing Dynasties.
1. Existing Ru ware vessels
After the Jurchens took over China's central plains and the Song was forced to move south, the kiln workers followed suit, and the kilns were abandoned. Since the Ru kilns made porcelain for imperial use under the Northern Song for a rather brief period, the number of Ru vessels that circulated in the world was small to begin with. Already during the Southern Song period, people lamented that they were “nearly impossible to find.” In the ninth fascicle of his Wulin jiushi (Old Matters from Wulin Garden), Zhou Mi (1232-1298), a Southern Song literatus, wrote that in 1151, when Emperor Gaozong visited the official residence of the Qinghe Commandery Prince Zhang Jun, Zhang presented the emperor a set of 16 Ru vessels, consisting of “one pair of wine bottles, one brush-washer, one incense-burner, one spherical sachet, four small cups, two large cups, one pair of incense pots, one large food canister, and one small food canister.” In the seventh fascicle of the same book, in a passage on the construction of Deshou Palace, we read that in 1179, when Emperor Gaozong attended a gathering in Jujing Garden, a sky-blue Ru vase had been placed on display there. From this we can tell that the Southern Song emperors were very fond of Ru porcelain vessels, and that they had already become rare, precious items at that time.
One may get a general idea of the number of Ru vessels stored in the Qing palace from Qinggong zaoban chu huoji qingdan (Files of the Workshop of the Qing Palace): “In the 27th day of the 4th month  eunuchs Liu Xiwen and Wang Taiping delivered a foreign lacquerware box and 29 Ru vessels [in fact, 31 vessels]. On inventory: one round, three-legged brush-washer; one round brush-washer with the inscription “Fenghua”; one footless brush-washer; eight numbered brush-washers with feet; two round brush-washers inscribed with the character bing; two round brush-washers without inscription; one round brush-washer with the inscription “Kunning”; one round brush-washer with no inscription; one round brush-washer with feet and no inscription; two round brush-washers with feet and no inscription; one round brush-washer with the inscription “Kunning”; two round brush-washers inscribed with the character bing; one round brush-washer with feet and no inscription; two large round brush-washers in the form of plates, with feet and no inscription; three large round brush-washers in the form of plates, with feet and no inscription; one round brush-washer with non-crackled glaze; one footed brush-washer with ewer mouth. It is decreed that for each object, a box with brown bamboo veneer and cushioning be made, and then packed inside lacquer boxes.” That is, a single delivery of Ru ware in 1729 contained as many as 31 items, and all were brush-washers, some in the form of plates. This was far more than the quantity that Zhang Jun had presented to Emperor Gaozong during the Southern Song.
How many Ru items have survived to the present? According to one source, Zhongguo taoci shi (History of Chinese Porcelain), “Fewer than 100 pieces have been passed down to the present day. of all the famous Song dynasty wares, it is the rarest variety.” A second source, Ruyao de faxian (The Discovery of the Ru Kilns), attaches a table that lists the details of 65 pieces that remain in the world, and it notes its collecting institution and the relevant sources. Based on the statistics I have compiled in recent years, there are approximately 74 surviving Ru porcelains, in 18 different varieties: mallet vases, “gall-shaped” or bottle vases, yuhuchun or pear-shaped bottle vases, narcissus vases, three-footed dishes, lotus blossom-shaped bowls, bowls with flared mouths, three-footed brush-washers, flat-bottomed brush-washers, brush-washers with round feet, oval brush-washers, brush-washers with floriate rims, shallow serving plates, deep serving plates, small dishes with flat bottoms, cups and trays with floriate rims, and cups and trays with round rims.
2. Vessel Forms and Ornamentations in Ru ware
During the Ru kiln excavations that took place from 2000 to 2002 at Qingliangsi, Baofeng, there were more than a few places found to have a layer as thick as 20 cm of porcelain sherds, and more than 98% of the sherds excavated were of Ru ware. The vessel forms, glaze colors, and the kind of kiln spurs or supports used in their making did not vary from the existing Ru vessels, so that one may say that all of the vessel forms seen among the preexisting Ru vessels were found at the kiln site. At the same time, a number of new vessel forms never seen before were discovered. The ten or so leading new forms were incense-burners, prunus vases, goose-neck vases, square pots, container boxes, cups and stands, lids, bowls, plates, basins, deep bowls, covered containers, and so on, and many of these forms had further subcategories. Among the forms excavated, some were in imitation of bronze vessels, like the three-footed zun, the three-footed brush-washer, the square pot, the round pot, and so on. There were also vessel forms used for display in the palace, such as narcissus basins, incense-burners, and varieties of vases and brush-washers. However, the largest categories of excavated vessels were those used for daily life: bowls, plates, basins, covered containers, container boxes, cups and stands, ewers, and so on.
There is an excavated Ru ware baluster vase with flared mouth, long neck, and cylindrical body; the surface has a sky-blue glaze with glossy texture and fine, sparse crackling. Glaze covers the bottom of the vessel, and there are five tiny marks from the support pins. Within the marks, the clay body is revealed to have an incense-ash color. The vessel shows good workmanship and a majestic shape, just like the so-called “mallet vases” that have circulated in the world to the present. There is a vase with a small, flaring mouth long, thin neck, rounded belly, and a round protruding base. The outstanding, beautiful form of this vessel is representative of the standards of workmanship for products of the Ru kilns. There is a deep-bellied brush-washer with flaring rim; the belly wall is straight and slanted, the bottom large and flat, and the short, round base protrudes outward. The clay body of the vessel is incense-ash grey, the glaze sky-blue and crackled over the entire surface. The marks of the support pins are concealed. It is comparable in beauty with the preexisting Ru vessels of the same kind. There is an incense-burner with a secondary opening, and on the belly are impressed three tiers of a lotus petal pattern. On the cinched waist are three protruding knobs, and around the base there are upward-curling shapes resembling the edges of lotus leaves. A pure sky-blue glaze covers the entire vessel body, except for an exposed round area on the bottom. This kind of incense-burner was shaped and assembled with the use of separate molds, so the techniques involved were complex. No other piece like it has been found at other kiln sites. In his Xuanhe fengshi Gaoli tu jing (Illustrated Record of Xuanhe Mission to Goryeo), the Song figure Xu Ke had this to say about Goryeo celadons: “There was a suanni dragon incense-burner, also of a halcyon color. The squatting beast was supported from below by a lotus blossom.” The incense-burners that are basically similar in form to this found among the Goryeo celadon ware of Korea clearly imitate the form of the Ru vessel.
Very few of the Ru vessels that had circulated in the world were ornamented. Except for a protruding ring around the surface of a cup and stand with a floriate rim, or the ridges around the body of a three-legged zun, there was only one oval brush-washer that had an incised twin fish pattern. By contrast, a number of the Ru ware vessels excavated at Qingliangsi, Baofeng have floral patterns on the surface. Among these, the lotus pattern appears most often. For example, there are mold-impressed upturned lotus patterns on the walls of an incense-burner, with lotus leaf shapes on the base, mold-impressed inverted lotus patterns on the walls of a cup stand, three tiers of lotus petals mold-impressed on the bellies of bowls and deep bowls, and entangled branches and lotus blossoms mold-impressed on the bellies of swan-necked vases. Next in frequency are dragon patterns. There are incised ascending dragons on the belly of a vase, incised coiled dragons on the lid of a container, mold-impressed coiled dragons on the interior bottom of a deep bowl that also has incised wave patterns on the outer surface. Next in frequency are twin fish patterns, seen for instance on the interior bottom of an oval brush-washer, and animal head appliqués holding rings, seen for example on the belly of a square pot. In addition, sculpted forms of mandarin ducks, ducks, dragons, lions, and so on have been discovered. These always appear in coiling or squatting form on the lids of incense-burners. They are realistic and feature exquisite workmanship.
I should also point out that a group of molds for basins, brush-washers, and incense-burners have also been excavated at the Ru kiln site of Qingliangsi, Baofeng, which shows that the Song dynasty had strict criteria on the dimensions of vessels for palace use. Many vessels were shaped with these molds. In general it has been thought that the official (Guan) kilns under the Palace Maintenance office of the Southern Song imitated the Ru ware. Historical records record that at the Palace Maintenance office's kiln, “Sedimentary clay was formed into molds of extremely precise workmanship.” This informs us that the demands on workmanship for palace-use articles were relentless, and cost was no object.
3. Distinctive Qualities of the Clay Bodies and Glazes of Ru ware
The clay bodies of Ru vessels are thin and have a light grey or greyish white color. Because the color is very close to that of incense after it is burnt, people often say that Ru ware has “incense ash-grey clay bodies.” However, the exposed surfaces of the sherds excavated at the Ru kiln site show a color that is closer to ochre or to whitish grey - this is the result of these sherds having been in contact with the soil and oxidizing over a long period of time. If one breaks these sherds, in the vast majority of cases the color of the new exposed surface is light grey or greyish white, and there are extremely few instances of brownish-grey or dark grey, so this is the true color of the clay bodies of Ru ware. In addition, the change in color of the vessel body is related to the firing temperature: if the firing temperature was low, the color is paler, but as the firing temperature increased, the color of the clay body would darken. If we compare Ru ware with other celadon ware in use among the ordinary people, we find that the Ru ware was somewhat underfired: the clay body is less dense; it is not baked to complete hardness; a broken surface will appear coarse and nonlustrous; the absorbency rate is fairly high; and there is an especially high number of bubbles of different sizes. These are some of the important criteria for examining fragments of Ru ware.
The lustrous, glossy glaze of Ru ware was applied rather thinly. Sometimes it appears translucent, sometimes opaque. There are many colors - sky-blue, powder-green, moon-white, eggshell-blue, green, and so on - but in generally they may be divided into two main categories: sky-blue and green. The color of the clay body has a definite effect in bringing out the color of the glaze. Powder-green, moon-white, and eggshell-blue that has a relatively good degree of transparency all present varying degrees of light grey, and on investigation this is due to the effect of the color of the clay body underneath. It is worth noting that extremely few green Ru ware pieces had been circulating in the world. From the large number of unearthed sherd artifacts that have been unearthed, the Ru kilns produced mainly sky-blue vessels, with a great amount of color variation, including powder-green, moon-white, and eggshell-blue. There is only a minor amount of color variation in the green glaze; basically it retained the original color.
In Chinese history, the Song dynasty is considered a very poor, weak period, since there was an uninterrupted stream of internal strife and incursions from outside. Within this particular historical context, the ruling class and literati began, as an escape from reality, to pursue a lifestyle of peace and pleasure and to cultivate elegant artistic tastes. The “School of Principle” of Cheng Hao (1032-1085) and Zhu Xi (1130-1200), which dominated the thinking of the time, advocated “preserving heavenly principle and nulling human desire.” It followed plain, unadorned style and the deep, mysterious philosophical principles of Chan Buddhism. In art this was reflected in a taste for mysticism and hoary antiquity, so that a transparently elegant artistic style became the mainstream. This so-called “literati taste” is also reflected in the kinds of porcelain vessels that the literati used - they were particular about purity of detail, luster, pure colors, simplicity of ornamentation, elegance, and they sought the mysterious, majestic artistic effect achieved by ancient bronzes. The color of the imperial-use celadon vessels from the Ru kiln is unshowy, subdued. The idea, implicit in their simplicity, of making one's mind and spirit calm precisely matched the Northern Song rulers’ aesthetic tastes, which favored blue-green colors.